Tumores: el virus que mata o cura

Robert was diagnosed with an inoperable glioma, leading to paralysis and speech issues. Despite regular treatment, the tumor grew, and doctors predicted a short lifespan. As a last resort, Robert tried an experimental treatment involving a modified herpes simplex virus injected into his brain. This virus targeted cancer cells while sparing normal tissue. The treatment stabilized the tumor, extending Robert's life by 12 years. Although he passed away in 2008, his trial paved the way for further research and helped other volunteers.

How did the researchers modify the virus used in Robert's treatment?

What was the outcome of Robert's groundbreaking experiment?